The Rant Bang Ur BB kit includes 2 precision R12 sealed bearings, 2 CNC machined 6061 aluminum cone spacers for a clean look, an aluminum internal spacer, 4 steel crank arm spacers for dialing in your chain alignment. - R12 Sealed bearings - 100% CNC 6061-T6 alloy cones - Include spacers for custom fit - Weight: 5.5 oz.